Intel 7260 problems on Thinkpad T440s

[Tim Hunter]

Very intermittent and inconsistent wireless connections. Occasionally the indicator will show that the connection has been lost, but more often it seems that the indicator just shows low signal strength -- as it generally does even when the connection is working well.

I'm pretty sure this is not an access-point problem because we have other devices using the same network without any problem.

Here's some of the additional information that has been requested in other discussions of similar problems, although I don't fully understand what all these results mean.

I have these three firmware files in /lib/firmware:
[code]
-rw-r--r-- 1 root root 683236 Nov 24 09:42 iwlwifi-7260-7.ucode
-rw-r--r-- 1 root root 679780 Dec 1 09:16 iwlwifi-7260-8.ucode
-rw-r--r-- 1 root root 680508 Dec 1 14:45 iwlwifi-7260-9.ucode
[/code]

dmesg | grep iwlwifi | grep firmware
[code]
[ 11.974201] iwlwifi 0000:03:00.0: loaded firmware version 22.24.8.0 op_mode iwlmvm
[/code]

lspci -nn | grep 0280
[code]
03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b2] (rev 83)
[/code]

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-52-generic 3.13.0-52.86
ProcVersionSignature: Ubuntu 3.13.0-52.86-generic 3.13.11-ckt18
Uname: Linux 3.13.0-52-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.10
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: timh 2011 F.... pulseaudio
                      timh 2801 F.... pulseaudio
 /dev/snd/controlC0: timh 2011 F.... pulseaudio
                      timh 2801 F.... pulseaudio
CurrentDesktop: XFCE
Date: Mon May 18 12:05:48 2015
HibernationDevice: RESUME=UUID=799c429f-edb4-438c-bbc7-386342199d23
InstallationDate: Installed on 2014-03-12 (432 days ago)
InstallationMedia: Xubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016)
MachineType: LENOVO 20ARCTO1WW
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-52-generic root=/dev/mapper/xubuntu--vg-root ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-52-generic N/A
 linux-backports-modules-3.13.0-52-generic N/A
 linux-firmware 1.127.11
SourcePackage: linux
UpgradeStatus: Upgraded to trusty on 2015-03-16 (63 days ago)
dmi.bios.date: 02/10/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: GJET71WW (2.21 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20ARCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0E50512 STD
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrGJET71WW(2.21):bd02/10/2014:svnLENOVO:pn20ARCTO1WW:pvrThinkPadT440s:rvnLENOVO:rn20ARCTO1WW:rvrSDK0E50512STD:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 20ARCTO1WW
dmi.product.version: ThinkPad T440s
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.1 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc3-vivid/

[Tim Hunter (timh-l)]

There doesn't seem to be anything here:
  http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc3-vivid/

But there is this:
  http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc3-unstable/
and these:
  http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc2-vivid/
  http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc1-vivid/

Which one should I try?

[Tim Hunter (timh-l)]

Added the tag "kernel-unable-to-test-upstream" just in case this is necessary for getting an answer to my question above about which kernel to try.

[Seth Forshee (sforshee)]

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc3-unstable/ is fine.

[Tim Hunter (timh-l)]

I'm not sure if this makes any sense but when I booted with the v4.1-rc3-unstable kernel it was as if the wireless card just wasn't detected at all. No sign of it in the network manager and no option to enable wi-fi.

There were some messages about iwlwifi firmware that appeared very briefly during booting, but too quickly for me to read. I could try again if that would be useful.

[Seth Forshee (sforshee)]

That's not enough to say that the bug exists upstream, as it sounds like there's some other issue.

I just tried this kernel:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.1-rc4-unstable/linux-image-4.1.0-040100rc4-generic_4.1.0-040100rc4.201505181436_amd64.deb

with Intel 7265 wifi (which uses the same driver) and it worked fine. Maybe give that one a try, and if you still have problems capture dmesg (e.g. run 'dmesg > dmesg.txt') before you reboot and attach it to this bug report. Thanks!

[Tim Hunter (timh-l)]

Aah, this one (4.1.0-040100rc4-generic) seems to fix the problem.

[penalvch (penalvch)]

Tim Hunter, the next step is to fully reverse commit bisect from kernel 3.19 to 4.1-rc4 in order to identify the last bad commit, followed immediately by the first good one. Once this commit has been identified, then it may be reviewed as a candidate for backporting into your release. Could you please do this following https://wiki.ubuntu.com/Kernel/KernelBisection#How_do_I_reverse_bisect_the_upstream_kernel.3F ?

Please note, finding adjacent kernel versions is not fully commit bisecting.

Thank you for your understanding.

Helpful bug reporting tips:
https://wiki.ubuntu.com/ReportingBugs

[Tim Hunter (timh-l)]

OK, I will do this, but it will take me a few days to get to it.

Could I ask, what are the pros and cons of using this working kernel in the meantime, before there is a "proper" (?) fix for this problem? I presume I should not install any of the updates I am automatically prompted about for now, because by installing this kernel I have moved off the sequence of machine states that is expected by whatever is sending me those updates? But other than that, if I try to just leave things as they are for a few weeks perhaps and use this working kernel, is there any risk of something else going wrong?

Thanks for all the help.

[Tony (byeaw24)]

I am also having this problem on a Lenovo laptop running trusty (14.04.2 LTS)
Now that the fix has been identified, will it be backported? What are the pros and cons of switching out the kernel?

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[pablo (pabloillescasburriel)]

same problem here wifi drops every time